title: ZnO nanoneedle/H2O solid-liquid heterojunction-based self-powered ultraviolet detector.
abstract: ZnO nanoneedle arrays were grown vertically on a fluorine-doped tin oxide-coated glass by hydrothermal method at a relatively low temperature. A self-powered photoelectrochemical cell-type UV detector was fabricated using the ZnO nanoneedles as the active photoanode and H2O as the electrolyte. This solid-liquid heterojunction offers an enlarged ZnO/water contact area and a direct pathway for electron transport simultaneously. By connecting this UV photodetector to an ammeter, the intensity of UV light can be quantified using the output short-circuit photocurrent without a power source. High photosensitivity, excellent spectral selectivity, and fast photoresponse at zero bias are observed in this UV detector. The self-powered behavior can be well explained by the formation of a space charge layer near the interface of the solid-liquid heterojunction, which results in a built-in potential and makes the solid-liquid heterojunction work in photovoltaic mode.
authors.affiliation: School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, People's Republic of China. cyx@sdu.edu.cn.
authors.forename: Qinghao
authors.initials: Q
authors.lastname: Li
authors.forename: Lin
authors.initials: L
authors.lastname: Wei
authors.forename: Yanru
authors.initials: Y
authors.lastname: Xie
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.forename: Dapeng
authors.initials: D
authors.lastname: Zhu
authors.forename: Jun
authors.initials: J
authors.lastname: Jiao
authors.forename: Yanxue
authors.initials: Y
authors.lastname: Chen
authors.forename: Shishen
authors.initials: S
authors.lastname: Yan
authors.forename: Guolei
authors.initials: G
authors.lastname: Liu
authors.forename: Liangmo
authors.initials: L
authors.lastname: Mei